Roof support for use in mines



May 17, 1932. F. cooKsoN ROOF SUPPORT FOR USE IN MINES Filed Novvl,V 1950 2'y Sheets-Sheet 1 Fig. 1. 1

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HTTORNEX May 17, 1932. F. cooKsoN ROOF SUPPORT FOR USE IN MINES Filed Nov.l, 1930 2 Sheets-Sheen 2 Fig. 7.

Dn.. ,WM Mm 0 K vzo Patented May 17, 1932 UNITED STATES FRANK COOKSON, F NEWCASTLE-ON-TYNE, ENGLAND ROOF SUPPORT FOR 'USE IN MINES Application filed November 1, 1930, Serial No. 492,785, and in- Great Britain November 23, 1929.

This invention relates to roof supports for use in mines, and more particularly to that kind of support used in connection with coal faces where conveyors are used, known as a chock and consisting of a number of blocks built up one on the other until the structure reaches the roof which it supports as the coal face advances and the roof tends to fall.

After the coal face has advanced, the roof pressure on the chocks becomes so great that before they can be removed the floor has to be dug out underneath the structure, or some of the blocks have to bey cut before the structure will collapse.

It is the object of the present invention to providemeans whereby with a simple operation the chock will automatically collapse under the pressure of the roof.

This object is attained according to the invention by providing one or more collapsible chock-pieces each of which comprises at its ends load carrying portions adapted to support the ends of other chockpieces atleast one of said load carrying portions comprising two wedge members having substantially the same wedge angles, oppositely arranged one on the other, and normally held together by means of quickly releasable catch means, the said collapsible chock-pieces being placed in position in the chock structure so that one wedge member is on top of the other and carries the load of the neXt chock-piece.

The collapsible chocks are preferably made of metal such as cast steel or cast iron; or they may be made of hardwood such as arrah wood. v j

The catch means may comprise a hook or hooks pivotally mounted on the one chockpiece member and engaging the other member to retain it in position.

The one chock-piece member or wedge member may be made separately and joined to a, chock-piece, or it may be madeintegral therewith, the other end of the chock-piece being left plain; or a wedge member may be joined to or made integral with each end of a chock-piece, giving a double-ended collapsible chock-piece.

To ensurethe chock-pieces above the collapsible chock-pieces falling clear, a transverse inclined lug may be formed on the stationary member of each collapsible chock, so

that any chock-pieces falling on these lugs Fig. 3 is a plan in half section of Fig. 1,

but with the slidable wedge member removed. Fig. 4: is a diagrammatic sketch showing a built-up chock withY the collapsible, chockpiece of Figs. 1 to 3 in position.

Fig. 5 is a sectional elevation of a doubleended form of collapsible chock-piece according to the invention.y y Fig. 6 is a plan in half section of Fig. 5.

Fig. 7 is another form of `double-ended chock-piece according to the invention, in secf tional elevation.

Fig. 8 is a plan in half section of Fig. 7

Fig. 9 is a sectional elevation of a double'- nded vchock-piece having a single catch mem- Fig. l0 is an end view of Fig. 9.

Fig. 11 is a detail view.

Referring more particularly to Figs. l to 3 of the drawings, l is the body of a hollow Vso chock-piece which is formed by casting'. The

one end is inclined at 2 as shown, while the other end is horizontal but preferably raised as shown at 3, to ensure sufficient release after the chock has been collapsed. Ridges 2a and 3a, 3?) are formed at the ends 2, 3 for the purpose of locating the ordinary woo-den chock-pieces.

This construction allows for excessive crushing of the chock-pieces due to abnormal roof pressures, so that in the event of f such crushing, the ultimate level of the lower face of the chock-piece resting on the collapsible chock will not be lower than that 0`f the body of the chock-piece. Y 1

The inclined end 2 is slottedcentrally to allow a hook 4 to project, the said hook being pivotally mounted between two bosses 5, 6 on the inside of the chock-piece.

A slidable complementary wedge member 7 having the same wedge angle or angle of inclination as that of the face 2 is adapted to rest on the said face 2, being oppositely disposed thereto. The said member 7 also preferably comprises a hollow casting, and has its horizontal face raised similarly to the corresponding face of the end 3. It is slotted centrally at its end' and inclined faces to allow of the passage of the hook 4 which engages an abutment lug 7a, on the member 7 to hold it in position. A lug 2?) on the chockpiece 2 engages with the slot in the inclined face of the wedge member 7 to maintain it in position laterally. Ridges 7 b serve to register the collapsible chock-pieces with the other chock-pieces. The collapsible chock-piece is preferably applied as shown in Fig. 4. Several chockpieces 8 are first built up in the usual way, say three tiers as shown, then a pair of collapsible chock-pieces 1 are laid in position as shown withthe wedge members 7 uppermost. -The projections 2a 3b are made to abut against the edges of the crosswise chockpieces on which they are placed, the projection 3b abutting against the outer edge of a chock-piece 8a which is placed out of vertical alignment with the other chock-pieces as shown. The chock structure is then completed in the usual manner.

When it is desired to remove the chock, the .ends of the hooks 4 are knocked up so as to clear the abutments 7a, whereupon the member 7 will slide down the end 2, andthe chockpieces above it will drop out of position. This Vwill allow thevbody of the collapsible chock to be tilted about the chock 8a owing to the roof pressure transmitted through the chockpieces over-hanging the said chock-piece 8a. The whole structure above the collapsible chocks will thus collapse automatically.

The lower tiers of the chock-structure up to and including the collapsible chock-pieces, may, if desired, be combined to form a single unit.

Figs. 5 and 6 show a form of collapsible chock-piece wherein both ends are collapsible. The ends are inclined as shown at 9 and 10 and have complementary wedges 11 and 12, both ends and wedges being ofsiinilar form to those described with 'reference to Figs. 1 to 3. The wedges are maintained in position by means of two hooks 13 and 14 pivoted about a common pin 15 in the body of the chock-piece. Alternatively, two independent hooks may be used, the arrangement in Fig. 1 being duplicated at `each end.

With this form of chock-piece, the chock structure is built up in the usual manner, the collapsible chock-pieces being laid say on the third tier as above set forth, but all the crosswise chock-pieces are in vertical alignment. To make the chock collapse each hook 13 and 14 is knocked up when the wedges 11 and 12 will slide out of position and the structure will collapse.

Figs. 7 and 8 show a double-ended chockpiece wherein the ends 16 and 17 are made separate and are connected by bars 18 and 19 and bolts 2O and 21.

The hooks 13 and 14 are freely linked together independently of the chock-piece, so that to release, one hook only need be knocked upwards.

Figs. 9 to 11 show a double-ended chockpiece of somewhat similar construction to that shown in Figs. 7 and 8 but with a single hook of special form. According to this arrangement, the end 22 has a catch piece 23 piVoted inside about a pin 24, the said catch piece being bifurcated as shown in Fig. 11 and connected at 25 between its two arms to the end of a hook 26 running the length of the chock-piece. The catch portion 23a of the catch piece 23 abuts against a lug 27a on the wedge 27 to hold the latter in position, while the hook 26 engages the other wedge 28 in the usual manner.

When it is desired to collapse the chock the hook 26 is knocked upwards with the result that the wedge 28 slips down to the right, while the wedge 27 slips down to the left, carries with it the catch piece 23 and causes it to'swing down to the left taking with it the hook 26, which drops inside theend 29 as shown in dotted lines.

In order to prevent chock-pieces dropping on the collapsible chock-pieces, there may be provided with transverse vertical deflectors having inclined surfaces extending for the width of the'chock-piece as shown for example in Figs. 9 and 10 at 30 and 31. Any falling objects will be deflected by the inclined surfaces of the members 30 and 31 and will thus fall clear of the chock-piece.

According to another form of double-ended checks the hooks may be comprised in a single rod passing through the length of the chock-block, and having turned down portions at each end which engage with the outside of the slidable members.

Where the inclination of the faces is rather gradual, an eye bolt may be provided on the one chock member, so that the latter maybe forcibly withdrawn to start the collapse of the structure.

I claim:

1. A horizontal chock-piece for usein chock structures for supporting the roofs of mines, comprising at its ends load carrying portions adapted to support the ends of other chock pieces, at least one of said load carrying portions comprising two wedge-shaped members having substantially the same wedge angles, said members being oppositely arranged one on the other, and quickly releasable catch means for normally holding the said members together.

2. A horizontal chock-piece according to claim 1, wherein the catch means comprise hook means pivotally mounted in the one chock-piece member and adapted at the hook portion to engage the other chock-piece member to retain it in position.

3. A horizontal chock-piece according to claim 1, wherein the wedge members are made separate from the chock-pieces, the lower member being adapted to be joined thereto.

4. A horizontal chock-piece according to claim 1, wherein the load carrying portions thereof are raised above the level of the rest of the chock-piece.

5. A horizontal chock-piece according to cla-im 1, and inclined deflecting means eX- tending for the width of the chock-piece.

6. A horizontal chock-piece according to claim 1, wherein the catch means comprise a single hook for each pair of wedge shaped members, said hook being pivotally mounted inside the chock-piece, slots in the wedgeshaped members adapted to receive said hook, and an abutment on the upper wedge member against which the hook end of the hook member is adapted to abut.

7 A horizontal collapsible chock-piece comprising two parallel bars connected at each end to the lower of two wedge-shaped members having substantially the same wedge angles, said members being oppositely arranged one on the other, central slots in said wedge-shaped members, a hook passing through said slots, said hook being adapted to engage the upper wedge-shaped member, while the two hooks are pivotally connected at their inner ends.

8. A horizontal chock-piece according to claim 8, wherein one of the hook members is pivotally mounted in the lower of one of the wedge-shaped members, an abutment inside the complementary upper wedge-shaped member towards the upper end thereof, said hook member being adapted to abut against said abutments when the said hook is substantially vertical, while the other hook member is pivot-ally mounted on said hook memberC1 between its hook portions and its pivotal en 9. A horizontal chock-piece according to claim 1, a recess on the one wedge-shaped member, and a projection on the other wedgeshaped member, the said recess and projection being adapted to interengage.

In witness whereof I have signed this specication.

FRANK COOKSON. 

